This is a 371 National Stage application of International Application No. PCT/SE2004/000100, filed Jan. 27, 2004, and claims priority to Swedish Patent Application No. 0300186-4, filed Jan. 27, 2003.
The present invention relates to a rotating electrical machine, comprising two mutually rotary main parts comprising of a stator and a rotor.
In prior art machines, regardless if the machine has been intended for use as a motor or as a generator, the rotor traditionally has been built around a central shaft rotatably journalled to the stator.
Also for very large diameter machines, the rotor has earlier traditionally been constructed and carried by the stator in said way. At such very large machines, e.g. electrical generators with a diameter of several meters, to be driven by low speed hydro turbines or wind turbines, these design principles have considerable drawbacks. Due to the need to achieve and maintain a high precision in the air gap between the rotor and the stator, which also for very large machines has to be quite small, and generally a few millimeters, one has to design the stator and the rotor very rigid and heavy. This means that the production costs will be very high. The largest achievable diameter is thus in practice quite limited.
Thus, the objective of the invention is to create an improved electrical machine of the type mentioned in the introduction, in which the drawbacks of the mentioned prior art machines can be avoided.